Of course I don't know. This is mere speculation. I just offer it for comments in case anyone's interested.

I came down with Graves' Disease 15 years ago after the very complicated birth of my daughter. Graves' runs in my family, and I know that physical stress can set it off, as well as childbirth, which makes the body produce many antibodies to prevent infection.

I did not radiate my thyroid, because I was having babies and nursing them. Instead, I took a thyroid suppressant (propylthiouracil), which sent me into several remissions, each one lasting longer. I had been in remission for about five years (my endo says I was due for a relapse) when I decided to lose weight. I lost 50 pounds in a year. I thought I was being prudent--I stuck to 1500 calories per day, avoided sugar and refined grains, ate lots of vegetables, and limited fat.

I also slowly and gradually started exercising, on an eliptical machine. I worked my way up very gradually to about 20 minutes a day.

All of this sounds very healthy and prudent, but I think it set my thyroid off again. I got a big surge of Graves' antibodies last summer. Then in the fall, my MG symptoms popped up. I speculate that the Graves' set off the MG.

Could I have avoided it? If I had destroyed my thyroid 15 years ago, would this have happened? Did I stress my body by losing weight and exercising?

Of course I don't really know. I don't think I did anything foolish. Obesity has its own dangers. Certainly it would have also been risky, in other ways, to stay out of shape. So this isn't about regrets. I'm just really interested in how all of this works, and trying to put together a coherent picture in my mind.